Is it ok for me to preen my birds tail?

My baby is 1.5 years old and he has a bone condition that affects flight and mobility. He can't open his wings or turn very far meaning his wing and tail feathers are always matted and pin feathery. I know in normal conditions you shouldn't preen them but he physically can't reach them and I don't want him to be uncomfortable but also don't want to cause any other issues.